It looks like he used a mask around the cloud text. You can either copy that mask and paste it to the sky and then invert it or copy the mask to a solid and use the solid as a track matte for the sky text.

I didn't find an answer, what i found is copymask2layer.. Again, what i want to do now, is to copy the position of the masks (cloud and sun) into the the sky "text" layer, preserving the mask position.